Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 165	$ 254	$ 500	$ 706
Postretirement and postemployment plans:
Change in actuarial gain (loss) in postretirement and postemployment plans	77	20	64	37
Income tax provision	39	0	39	0
Postretirement and postemployment plans, net of tax	38	20	25	37
Foreign currency translation:
Foreign currency translation adjustment related to sale of U.K. business	30	0	30	0
Income tax provision	(7)	0	(7)	0
Foreign currency translation, net of tax	23	0	23	0
Other, net of tax	1	0	1	4
Other comprehensive income	62	20	49	41
Comprehensive income	$ 227	$ 274	$ 549	$ 747